#include <bits/stdc++.h>
using namespace std;
void f(int * a,int n,int x){
for(int i=0;i<n;i++)
{
if (a[i]==x){
cout <<x <<" Found at "<<i<<endl;
return;}
}
cout <<x <<" Not Found"<<endl;
}
int main(){
int t;
cin >>t;
while(t--){
int n;
cin >>n;
int *a =new int[n];
for(int i=0;i<n;i++)
cin >>a[i];
int x;
cin >>x;
f(a,n,x);
}
return 0;
}
#include <bits/stdc++.h>
using namespace std;
int f(int * a,int n,int x){
for(int i=0;i<n;i++)
{
if (a[i]==x)
return i;
}
return -1;
}
int main(){
int t;
cin >>t;
while(t--){
int n;
cin >>n;
int *a =new int[n];
for(int i=0;i<n;i++)
cin >>a[i];
int x;
cin >>x;
int found = f(a,n,x);
if (found == -1)
cout <<x << " Not found"<<endl;
else
cout <<x << " found at index "<< found << endl;
}
return 0;
}
Linear search using vector
#include <bits/stdc++.h>
using namespace std;
int linear_search(vector<int> v1,int n,int key){
vector<int>::iterator it;
it = find(v1.begin(), v1.end(), key);
if(it != v1.end())
return (it - v1.begin());
else
return -1;
}
int main(){
int t;
cin >>t;
while(t--){
int n,a;
cin>>n;
vector<int> v1;
for(int i=0;i<n;i++){
cin>>a;
v1.push_back(a);
}
int key;
cin>>key;
int index = linear_search(v1,n,key);
if(index!=-1)
cout<<key <<" is present at index "<< index <<endl;
else
cout<<key <<" is NOT Found!" <<endl;
}
return 0;
}
Binary search
#include <bits/stdc++.h>
using namespace std;
int binary_search(int arr[],int n,int key){
//Implement binary search
int s = 0;
int e = n - 1;
while(s<=e){
int mid = (s+e)/2;
if(arr[mid] == key){
return mid;
}
else if(arr[mid] > key){
e = mid - 1;
}
else{
s = mid + 1;
}
}
return -1;
}
int main(){
int t;
cin >>t;
while(t--){
int n;
cin >>n;
int *a =new int[n];
for(int i=0;i<n;i++)
cin >>a[i];
int x;
cin >>x;
int index = binary_search(a,n,x);
if (index == -1)
cout <<x << " Not found"<<endl;
else
cout <<x << " found at index "<< index << endl;
}
return 0;
}
Binary search using vector
#include <bits/stdc++.h>
using namespace std;
int f(vector<int> v,int n,int key){
//Implement binary search
auto it = lower_bound(v.begin(), v.end(), key);
if (it == v.end() || *it != key) {
return -1;
} else {
int index = std::distance(v.begin(), it);
return index;
}
}
int main(){
int t;
cin >>t;
while(t--){
int n,a;
cin>>n;
vector<int> v1;
for(int i=0;i<n;i++){
cin>>a;
v1.push_back(a);
}
int key;
cin>>key;
int index = f(v1,n,key);
if(index!=-1)
cout<<key <<" is present at index "<< index <<endl;
else
cout<<key <<" is NOT Found!" <<endl;
}
return 0;
}
Write, Run & Share C++ code online using OneCompiler's C++ online compiler for free. It's one of the robust, feature-rich online compilers for C++ language, running on the latest version 17. Getting started with the OneCompiler's C++ compiler is simple and pretty fast. The editor shows sample boilerplate code when you choose language as C++ and start coding!
OneCompiler's C++ online compiler supports stdin and users can give inputs to programs using the STDIN textbox under the I/O tab. Following is a sample program which takes name as input and print your name with hello.
#include <iostream>
#include <string>
using namespace std;
int main()
{
string name;
cout << "Enter name:";
getline (cin, name);
cout << "Hello " << name;
return 0;
}
C++ is a widely used middle-level programming language.
When ever you want to perform a set of operations based on a condition If-Else is used.
if(conditional-expression) {
//code
}
else {
//code
}
You can also use if-else for nested Ifs and If-Else-If ladder when multiple conditions are to be performed on a single variable.
Switch is an alternative to If-Else-If ladder.
switch(conditional-expression){
case value1:
// code
break; // optional
case value2:
// code
break; // optional
......
default:
code to be executed when all the above cases are not matched;
}
For loop is used to iterate a set of statements based on a condition.
for(Initialization; Condition; Increment/decrement){
//code
}
While is also used to iterate a set of statements based on a condition. Usually while is preferred when number of iterations are not known in advance.
while (condition) {
// code
}
Do-while is also used to iterate a set of statements based on a condition. It is mostly used when you need to execute the statements atleast once.
do {
// code
} while (condition);
Function is a sub-routine which contains set of statements. Usually functions are written when multiple calls are required to same set of statements which increases re-usuability and modularity. Function gets run only when it is called.
return_type function_name(parameters);
function_name (parameters)
return_type function_name(parameters) {
// code
}